Coronary Microcirculatory Dysfunction in People With HIV and Its Association With Antiretroviral Therapy.

BACKGROUND: HIV infection and abacavir-containing antiretroviral regimens are associated with vascular endothelial dysfunction and increased cardiovascular risk. Positron emission tomography (PET)-derived myocardial blood flow reserve (MBFR), the ratio of vasodilator stress to rest myocardial blood flow, is a well-validated measure of coronary microvascular health and marker of cardiovascular risk. Our objective was to compare MBFR among people with HIV (PWH) with matched non-HIV controls and to assess whether switching from dolutegravir/lamivudine/abacavir to the non-abacavir regimen bictegravir/emtricitabine/tenofovir alafenamide (TAF) would improve MBFR. METHODS AND RESULTS: Thirty-seven PWH were 1:2 matched on cardiovascular risk factors to 75 people without HIV, and MBFR corrected for differences in resting hemodynamics was compared in a cross-sectional design. PWH were majority men (68%) with a mean age of 56 years. Mean stress myocardial blood flow (1.83 mL/min per g [95% CI, 1.68-1.98] versus 2.40 mL/min per g [95% CI, 2.25-2.54]; P<0.001) and MBFR (2.18 [95% CI, 1.96-2.40] versus 2.68 [95% CI, 2.47-2.89]; P=0.002) was significantly lower in PWH than in people without HIV. In a single-arm, multicenter trial, a subset of 25 PWH who were virologically suppressed on dolutegravir/lamivudine/abacavir underwent positron emission tomography myocardial perfusion imaging at baseline and after switching to bictegravir/emtricitabine/TAF. MBFR was unchanged after switching to bictegravir/emtricitabine/TAF for a mean of 27 weeks (MBFR, 2.34 to 2.29; P=0.61), except in PWH with impaired MBFR at baseline (<2.00; N=6) in whom MBFR increased from 1.58 to 2.02 (P=0.02). CONCLUSIONS: PWH had reduced coronary microvascular function compared with controls without HIV. Coronary microvascular function did not improve after switching from dolutegravir/lamivudine/abacavir to bictegravir/emtricitabine/TAF. REGISTRATION: URL: https://www.clinicaltrials.gov; unique identifier: NCT03656783.

Integrase Inhibitor Use Associated with Weight Gain in Women and Incident Diabetes Mellitus.

Excessive weight gain associated with integrase strand transfer inhibitor (InSTI) antiretrovirals is an emerging issue; however, the metabolic consequences of this effect have not been established. Our objective was to evaluate for InSTI-emergent weight gain and potential associated type 2 diabetes mellitus (T2DM) among a diverse HIV patient cohort. For this retrospective cohort study, we obtained clinical warehouse data for HIV+ patients between fiscal years 2007-17. We compared patients initiated on an InSTI with those started on an alternate regimen. Our primary outcome was percentage weight change from baseline to 24 months postinitiation using the linear mixed-effects model fit by restricted maximum likelihood. Our secondary outcome was incident T2DM as defined by a new prescription for antihyperglycemic medication within 18 months after antiretroviral therapy (ART) start. Diabetes-free survival was estimated using the Kaplan-Meier method, log-rank test, and Cox proportional-hazards model. The cohort included 1,235 individuals initiating ART, 136 (11.0%) with an InSTI. InSTI use in women was significantly associated with greater weight gain compared with non-InSTIs (11.0%, 95% confidence interval, CI: 5.22 to 16.8, p < .01), after adjusting for potential confounding variables. In a univariate analysis, InSTI use was associated with more incident T2DM diagnoses compared with non-InSTI regimens (unadjusted hazard ratio = 3.27, p = .01), although incident T2DM was not associated with weight gain. InSTIs were significantly associated with weight gain among females. We also observed an increased risk of incident diabetes mellitus among both sexes, however, unrelated to weight changes. Further prospective studies will be necessary to confirm this finding and investigate its mechanism.

Intragenic proviral elements support transcription of defective HIV-1 proviruses.

HIV-1 establishes a persistent proviral reservoir by integrating into the genome of infected host cells. Current antiretroviral treatments do not target this persistent population of proviruses which include latently infected cells that upon treatment interruption can be reactivated to contribute to HIV-1 rebound. Deep sequencing of persistent HIV proviruses has revealed that greater than 90% of integrated HIV genomes are defective and unable to produce infectious virions. We hypothesized that intragenic elements in the HIV genome support transcription of aberrant HIV-1 RNAs from defective proviruses that lack long terminal repeats (LTRs). Using an intact provirus detection assay, we observed that resting CD4+ T cells and monocyte-derived macrophages (MDMs) are biased towards generating defective HIV-1 proviruses. Multiplex reverse transcription droplet digital PCR identified env and nef transcripts which lacked 5' untranslated regions (UTR) in acutely infected CD4+ T cells and MDMs indicating transcripts are generated that do not utilize the promoter within the LTR. 5'UTR-deficient env transcripts were also identified in a cohort of people living with HIV (PLWH) on ART, suggesting that these aberrant RNAs are produced in vivo. Using 5' rapid amplification of cDNA ends (RACE), we mapped the start site of these transcripts within the Env gene. This region bound several cellular transcription factors and functioned as a transcriptional regulatory element that could support transcription and translation of downstream HIV-1 RNAs. These studies provide mechanistic insights into how defective HIV-1 proviruses are persistently expressed to potentially drive inflammation in PLWH.

Pandemic Response Requires Research Samples: A U.S. Safety-Net Hospital's Experience and Call for National Action.

Biorepositories provide a critical resource for gaining knowledge of emerging infectious diseases and offer a mechanism to rapidly respond to outbreaks; the emergence of the novel coronavirus, SARS-CoV-2, has proved their importance. During the COVID-19 pandemic, the absence of centralized, national biorepository efforts meant that the onus fell on individual institutions to establish sample repositories. As a safety-net hospital, Boston Medical Center (BMC) recognized the importance of creating a COVID-19 biorepository to both support critical science at BMC and ensure representation in research for its urban patient population, most of whom are from underserved communities. This article offers a realistic overview of the authors' experience in establishing this biorepository at the onset of the COVID-19 pandemic during the height of the first surge of cases in Boston, Massachusetts, with the hope that the challenges and solutions described are useful to other institutions. Going forward, funders, policymakers, and infectious disease and public health communities must support biorepository implementation as an essential element of future pandemic preparedness.

Age at Diagnosis of Heart Failure in United States Veterans With and Without HIV Infection.

Background Although HIV is associated with increased risk of heart failure (HF), it is not known if people living with HIV develop HF at a younger age compared with individuals without HIV. Crude comparisons of age at diagnosis of HF between individuals with and without HIV does not account for differences in underlying age structures between the populations. Methods and Results We used Veterans Health Administration data to compare the age at HF diagnosis between veterans with and without HIV, with adjustment for difference in population age structure. Statistical weights, calculated for each 1-year strata of veterans with HIV in each calendar year from 2000 to 2018, were applied to the veterans without HIV to standardize the age structure. We identified 5093 veterans with HIV (98% men, 34% White) with first HF episode recorded after HIV diagnosis (median age at incidence of HF, 58 years), and 1 425 987 veterans without HIV (98% men, 78% White) with HF (corresponding age, 72 years), with an absolute difference of 14 years. After accounting for difference in age structure, the adjusted median age at HF diagnosis for veterans without HIV was 63 years, 5 years difference with veterans with HIV (P<0.001). The age differences were consistent across important subgroups such as preserved versus reduced ejection fraction and inpatient versus outpatient index HF. Conclusions Veterans with HIV are diagnosed with HF at a significantly younger age compared with veterans without HIV. These findings may have implications for HF prevention in individuals with HIV. Future studies are needed to make the findings more generalizable.

Novel ELISA Protocol Links Pre-Existing SARS-CoV-2 Reactive Antibodies With Endemic Coronavirus Immunity and Age and Reveals Improved Serologic Identification of Acute COVID-19 via Multi-Parameter Detection.

The COVID-19 pandemic has drastically impacted work, economy, and way of life. Sensitive measurement of SARS-CoV-2 specific antibodies would provide new insight into pre-existing immunity, virus transmission dynamics, and the nuances of SARS-CoV-2 pathogenesis. To date, existing SARS-CoV-2 serology tests have limited utility due to insufficient reliable detection of antibody levels lower than what is typically present after several days of symptoms. To measure lower quantities of SARS-CoV-2 IgM, IgG, and IgA with higher resolution than existing assays, we developed a new ELISA protocol with a distinct plate washing procedure and timed plate development via use of a standard curve. Very low optical densities from samples added to buffer coated wells at as low as a 1:5 dilution are reported using this 'BU ELISA' method. Use of this method revealed circulating SARS-CoV-2 receptor binding domain (RBD) and nucleocapsid protein (N) reactive antibodies (IgG, IgM, and/or IgA) in 44 and 100 percent of pre-pandemic subjects, respectively, and the magnitude of these antibodies tracked with antibody levels of analogous viral proteins from endemic coronavirus (eCoV) strains. The disease status (HIV, SLE) of unexposed subjects was not linked with SARS-CoV-2 reactive antibody levels; however, quantities were significantly lower in subjects over 70 years of age compared with younger counterparts. Also, we measured SARS-CoV-2 RBD- and N- specific IgM, IgG, and IgA antibodies from 29 SARS-CoV-2 infected individuals at varying disease states, including 10 acute COVID-19 hospitalized subjects with negative serology results by the EUA approved Abbott IgG chemiluminescent microparticle immunoassay. Measurements of SARS-CoV-2 RBD- and N- specific IgM, IgG, IgA levels measured by the BU ELISA revealed higher signal from 9 of the 10 Abbott test negative COVID-19 subjects than all pre-pandemic samples for at least one antibody specificity/isotype, implicating improved serologic identification of SARS-CoV-2 infection via multi-parameter, high sensitive antibody detection. We propose that this improved ELISA protocol, which is straightforward to perform, low cost, and uses readily available commercial reagents, is a useful tool to elucidate new information about SARS-CoV-2 infection and immunity and has promising implications for improved detection of all analytes measurable by this platform.

Early administration of interleukin-6 inhibitors for patients with severe COVID-19 disease is associated with decreased intubation, reduced mortality, and increased discharge.

OBJECTIVE: The aim of this observational study was to determine the optimal timing of interleukin-6 receptor inhibitor (IL6ri) administration for coronavirus disease 2019 (COVID-19). METHODS: Patients with COVID-19 were given an IL6ri (sarilumab or tocilizumab) based on iteratively reviewed guidelines. IL6ri were initially reserved for critically ill patients, but after review, treatment was liberalized to patients with lower oxygen requirements. Patients were divided into two groups: those requiring ≤45% fraction of inspired oxygen (FiO2) (termed stage IIB) and those requiring >45% FiO2 (termed stage III) at the time of IL6ri administration. The main outcomes were all-cause mortality, discharge alive from hospital, and extubation. RESULTS: A total of 255 COVID-19 patients were treated with IL6ri (149 stage IIB and 106 stage III). Patients treated in stage IIB had lower mortality than those treated in stage III (adjusted hazard ratio (aHR) 0.24, 95% confidence interval (CI) 0.08-0.74). Overall, 218 (85.5%) patients were discharged alive. Patients treated in stage IIB were more likely to be discharged (aHR 1.43, 95% CI 1.06-1.93) and were less likely to be intubated (aHR 0.43, 95% CI 0.24-0.79). CONCLUSIONS: IL6ri administration prior to >45% FiO2 requirement was associated with improved COVID-19 outcomes. This can guide clinical management pending results from randomized controlled trials.

Infectious Myelitis.

Myelitis refers to inflammation of the spinal cord which can result in a spectrum of neurologic impairment. Infectious pathogens are an important etiologic category, and can result in myelitis through direct pathogenic effect or through immune-mediated parainfection; this review focuses on the former category. The spectrum of clinical manifestations is summarized and a diagnostic workup provided to aid clinicians in developing an approach to patients presenting with symptoms suggestive of infectious myelitis. This is followed by an overview of the important viral, bacterial, parasitic, and fungal causes of infectious myelitis. The typical presentations, diagnostic modalities, and treatment approaches are outlined for key pathogens culprit in infectious myelitis to allow clinicians to promptly recognize and diagnose specific infectious etiologies of myelitis.

Immunological and Neurometabolite Changes Associated With Switch From Efavirenz to an Integrase Inhibitor.

BACKGROUND: The biological mechanisms by which efavirenz (EFV) causes central nervous system (CNS) effects are unclear. The objective of this pilot study was to elucidate the mechanisms underlying these CNS effects by correlating well-described neuropsychological (NP) changes with neurometabolites and immunologic markers following switch off EFV. SETTING: Two single-arm parallel switch studies among HIV-infected adults in Boston, USA, from 2015 to 2017. METHODS: Twenty asymptomatic HIV-infected adults on EFV-containing regimens were switched to an integrase strand transfer inhibitor-based regimen for 8 weeks. NP assessments were conducted before and after switch and correlated with neurometabolite changes measured using magnetic resonance spectroscopy and immunological markers. All pre-EFV and post-EFV measures were evaluated using matched-paired analyses. RESULTS: NP testing demonstrated improvement in the domains of mood, cognition, and sleep off EFV. Magnetic resonance spectroscopy revealed decreases in the neurometabolite glutathione level (P = 0.03), a marker of oxidative stress after switch. Inhibitory neuronal activity as reflected by gamma-amino butyric acid levels increased (P = 0.03), whereas excitatory neurotransmitters glutamine + glutamate (Glx) and aspartate decreased (P = 0.04, 0.001). Switching off EFV was also associated with changes in inflammatory markers; plasma markers sCD14 (P = 0.008) decreased, whereas I-FABP and TNFRI levels increased (P = 0.05, 0.03). Cellular markers CD4 and CD8 HLA-DR-/CD38 subsets both increased (P = 0.05, 0.02). CONCLUSIONS: Even asymptomatic participants showed improvements in NP parameters when switched off EFV. These improvements were associated with decreased CNS oxidative stress and excitatory neuronal activity. Changes in immune activation biomarkers suggested overall decreased inflammation. EFV may exert CNS effects through oxidative and inflammatory pathways, providing insight into possible mechanisms of EFV neurotoxicity.

Elevated Levels of Microbial Translocation Markers and CCL2 Among Older HIV-1-Infected Men.

The aging of the human immunodeficiency virus type 1 (HIV-1)-infected population obligates a focus on the interaction between aging, comorbid conditions, and HIV-1. We recruited a cohort of HIV-1-infected men aged ≤ 35 years or ≥ 50 years who were receiving fully suppressive antiretroviral therapy (ART). We analyzed plasma markers of inflammation; T-cell activation, exhaustion, proliferation; and innate cellular subsets and functional capacity. Levels of lipopolysaccharide and the plasma marker of chemokine (C-C motif) ligand 2 were significantly elevated in older HIV-infected men despite comparable cellular phenotypes. Compared with similarly age-stratified uninfected subjects, older HIV-1-infected adults were also more frequently in the upper quartile of soluble CD14 expression.

Genome-Wide Association Study of Human Immunodeficiency Virus (HIV)-1 Coreceptor Usage in Treatment-Naive Patients from An AIDS Clinical Trials Group Study.

OBJECTIVES: We conducted a genome-wide association study to explore whether common host genetic variants (>5% frequency) were associated with presence of virus able to use CXCR4 for entry. METHODS: Phenotypic determination of human immunodeficiency virus (HIV)-1 coreceptor usage was performed on pretreatment plasma HIV-1 samples from treatment-naive participants in AIDS Clinical Trials Group A5095, a study of initial antiretroviral regimens. Associations between genome-wide single-nucleotide polymorphisms (SNPs), CCR5 Δ32 genotype, and human leukocyte antigen (HLA) class I alleles and viral coreceptor usage were explored. RESULTS: Viral phenotypes were obtained from 593 patients with available genome-wide SNP data. Forty-four percent of subjects had virus capable of using CXCR4 for entry as determined by phenotyping. Overall, no associations, including those between polymorphisms in genes encoding viral coreceptors and their promoter regions or in HLA genes previously associated with HIV-1 disease progression, passed the statistical threshold for genome-wide significance (P < 5.0 × 10(-8)) in any comparison. However, the presence of viruses able to use CXCR4 for entry was marginally associated with the CCR5 Δ32 genotype in the nongenome-wide analysis. CONCLUSIONS: No human genetic variants were significantly associated with virus able to use CXCR4 for entry at the genome-wide level. Although the sample size had limited power to definitively exclude genetic associations, these results suggest that host genetic factors, including those that influence coreceptor expression or the immune pressures leading to viral envelope diversity, are either rare or have only modest effects in determining HIV-1 coreceptor usage.

Long-term reduction in peripheral blood HIV type 1 reservoirs following reduced-intensity conditioning allogeneic stem cell transplantation.

BACKGROUND: The long-term impact of allogeneic hematopoietic stem cell transplantation (HSCT) on human immunodeficiency virus type 1 (HIV-1) reservoirs in patients receiving combination antiretroviral therapy (cART) is largely unknown. METHODS: We studied the effects of a reduced-intensity conditioning allogeneic HSCT from donors with wild-type-CCR5(+) cells on HIV-1 peripheral blood reservoirs in 2 patients heterozygous for the ccr5Δ32 mutation. In-depth analyses of the HIV-1 reservoir size in peripheral blood, coreceptor use, and specific antibody responses were performed on samples obtained before and up to 3.5 years after HSCT receipt. RESULTS: Although HIV-1 DNA was readily detected in peripheral blood mononuclear cells (PBMCs) before and 2-3 months after HSCT receipt, HIV-1 DNA and RNA were undetectable in PBMCs, CD4(+) T cells, or plasma up to 21 and 42 months after HSCT. The loss of detectable HIV-1 correlated temporally with full donor chimerism, development of graft-versus-host disease, and decreases in HIV-specific antibody levels. CONCLUSIONS: The ability of donor cells to engraft without evidence of ongoing HIV-1 infection suggests that HIV-1 replication may be fully suppressed during cART and does not contribute to maintenance of viral reservoirs in peripheral blood in our patients. HSCTs with wild-type-CCR5(+) donor cells can lead to a sustained reduction in the size of the peripheral reservoir of HIV-1.

Env sequence determinants in CXCR4-using human immunodeficiency virus type-1 subtype C.

HIV-1 subtype C (HIV-1C) CXCR4-using virus is isolated infrequently and is poorly characterized. Understanding HIV-1C env characteristics has implications for the clinical use of antiretrovirals that target viral entry. A total of 209 env clones derived from 10 samples with mixed CCR5-(R5), CXCR4-using (X4) or dual-tropic HIV-1C were phenotyped for coreceptor usage. Intra-patient X4 and R5 variants generally formed distinct monophyletic phylogenetic clusters. X4 compared to R5 envs had significantly greater amino acid variability and insertions, higher net positive charge, fewer glycosylation sites and increased basic amino acid substitutions in the GPGQ crown. Basic amino acid substitution and/or insertion prior to the crown are highly sensitive characteristics for predicting X4 viruses. Chimeric env functional studies suggest that the V3 loop is necessary but often not sufficient to impart CXCR4 utilization. Our studies provide insights into the unique genotypic characteristics of X4 variants in HIV-1C.

Prevalence and clinical associations of CXCR4-using HIV-1 among treatment-naive subtype C-infected women in Botswana.

HIV-1 coreceptor use was determined using a phenotypic assay in plasma samples from treatment-naive women infected with subtype C virus who had CD4 cell counts below 200 cells/mm3. Of 148 women, 14.9% were infected with dual/mixed virus; the remainder had R5 virus. A greater proportion of women in the lowest CD4 cell count stratum had dual/mixed virus (P = 0.026); change in coreceptor use after antiretroviral therapy exposure was uncommon. CXCR4-using HIV-1 was less common in subtype C-infected women than reported in subtype B cohorts but was most prevalent in women with the lowest CD4 cell counts.

Xenotropic murine leukemia virus-related virus prevalence in patients with chronic fatigue syndrome or chronic immunomodulatory conditions.

We investigated the prevalence of xenotropic murine leukemia virus-related virus (XMRV) among 293 participants seen at academic hospitals in Boston, Massachusetts. Participants were recruited from the following 5 groups of patients: chronic fatigue syndrome (n = 32), human immunodeficiency virus infection (n = 43), rheumatoid arthritis (n = 97), hematopoietic stem-cell or solid organ transplant (n = 26), or a general cohort of patients presenting for medical care (n = 95). XMRV DNA was not detected in any participant samples. We found no association between XMRV and patients with chronic fatigue syndrome or chronic immunomodulatory conditions.

The design and validation of a novel phenotypic assay to determine HIV-1 coreceptor usage of clinical isolates.

A phenotypic assay to determine coreceptor usage of HIV-1 has been developed for rapid testing of clinical samples. The assay is based on the synthesis of viral stock from full-length env amplicons isolated from patient's plasma. Pseudoviral stock is generated rapidly by using an overlapping PCR method to assemble a CMV promoter to env, followed by co-transfection into producer cells with a HIV plasmid (pNL4-3.Luc.R(-)E(-)) containing a non-functional env. The coreceptor used by the viral quasispecies is tested by infection into U87.CD4.CCR5 and U87.CD4.CXCR4 cells. Viral entry is indicated by the expression of the luciferase gene in relative light units (RLU). The use of CXCR4 coreceptor by minor variants is confirmed with sufficient suppression of RLU by a CXCR4 inhibitor. Two statistical tests are employed to confirm viral entry. This assay accurately assigned coreceptor usage of isolates of various subtypes and in the majority of samples of various viral loads. The sensitivity to detect minor species of CXCR4-using env is 1% at higher viral loads and 5% at less than 1,000 copies/ml. This assay provides a sensitive, efficient and relatively low-cost approach suitable for use by research laboratories for assessing HIV-1 coreceptor usage of plasma samples.

Tropism testing in the clinical management of HIV-1 infection.

PURPOSE OF REVIEW: A variety of methods are available to determine HIV-1 co-receptor usage, commonly referred to as viral tropism. This article reviews recent data on phenotypic and genotypic assays of HIV-1 tropism. RECENT FINDINGS: Tropism assays are used to determine co-receptor usage of HIV-1 in patients who may be candidates for treatment with CCR5 antagonists. Phenotypic assays are used most often in the clinical trials of CCR5 antagonists, and are considered the 'gold standard' for comparison with other methods of tropism testing. Enhancements have allowed detection of a lower threshold of minor CXCR4-using species. When compared with phenotypic assays, genotypic methods have poor sensitivity but good specificity at detecting CXCR4-using HIV-1. Preliminary results from a recent comparative study suggest that some genotypic methods may perform as well as phenotypic tests in predicting virologic response to CCR5 antagonists. Several studies show that tropism testing may provide useful prognostic information regarding the risk of disease progression. SUMMARY: Understanding the characteristic of different tropism assays is important for their clinical use. Although phenotypic testing currently is favored, genotypic assays may be a suitable alternative in appropriate settings.